1. Field of the Invention
This invention relates to the insulation of structures and similar insulation applications and more particularly, to insulation configurations for ceiling and floor structures. Through extensive tests, it has surprisingly been determined that the efficiency of low density, loose-fill , particulate, blown insulation, as well as low density fiber batt insulation, is greatly improved by placing additional similarly constituted high density insulation containing fiberglass or other insulation, over and under the low density insulation, depending upon the attic or floor application, to isolate the low density insulation and produce layered high density-low density insulation configurations of surprisingly high efficiency.
Recent extensive tests and studies have determined that current test methods for measuring the efficiency of insulation do not accurately predict the "in place performance" of low density fiber, loose-fill, particulate, blown insulation. The three current test methods commonly used in the industry to measure performance of insulation are the "Guarded Hot Plate", "Guarded Hot Box" and the "Calibrated Hot Box" techniques. All three test methods induce heat on one side of the insulation while the insulation is contained and not exposed to the atmosphere and measure the heat which passes through the insulation. From these tests, a thermal conductivity coefficient, (K) is determined and this thermal conductivity coefficient is used to calculate the thermal resistance, (R) of the insulation. These data are then used by architects and engineers to design and predict the thermal efficiency of structures.
2. Description of the Prior Art
In the construction of homes, buildings and other structures, wall configurations are typically assembled from vertical studs and insulation is placed between the studs. It is generally assumed that this insulation prevents air circulation between the studs. However, in contradiction to this technology, conventional wall construction provides for "weep" or ventilation holes at the bottom of the wall and the insulation is thusly vented to the attic, to permit the wall to "breathe". The discoveries outlined in this application make it reasonable to assume that this "breathing" of the wall deteriorates the efficiency of the insulation to a degree much greater than expected. The "breathing", or heat-induced natural convection, also exists in the low density, loose-fill particulate or fiber batt insulation in attics and under floors and can be reduced by placing high density horizontal batt or pillow insulation barriers over or under the low density insulation, to seal the insulation from convection and create high efficiency, layered insulation configurations characterized by closed cells within the attic and floor structures. The teachings of this invention thus dictate that the first reason these layered insulation configurations are more thermally efficient, is that air is more easily trapped in the low density insulation layer. Secondly, the high density-low density layers combine in a synergistic manner to create more efficiency than is possible in a homogeneous layer of insulation of the same thickness. Consequently, according to a preferred embodiment of this invention, the layers of insulation are combined to incorporate a first layer of fibrous, loose-fill, particulate, blown insulation of high density over or under a low density insulation layer, depending upon location, to provide more thermally efficient insulation configurations.
In order to better understand the phenomena which take place in the insulation configurations of this invention, a highly effective apparatus was designed for conducting tests which accurately measure and predict the "in place performance" of fiber insulation layered according to this invention in building structures. The test results are outlined in FIG. 6 of the drawings.
Various types of insulation configurations have been patented over the years. Typical of these insulation configurations is the "Wall Insulation" detailed in U.S. Pat. No. 2,283,257, dated May 19, 1942, to M. A. Jorsch. The wall insulation includes inner and outer sheets of cellular fiberboard located within a wall to form a chamber between the sheets, which chamber acts as a dead air space and increases the insulation efficiency of the wall. U.S. Pat. No. 2,804,657, dated Sep. 3, 1957, to C. G. Munters, details "Heat Insulated Walls of Cold-Storage Rooms." The heat insulated walls include a spaced outer casing and an inner lining, with a diffusion barrier located adjacent to the casing on the iiner side and further including heat insulating material located between the casing and the lining. U.S. Pat. No. 4,047,346, dated Sep. 13, 1977, to Robert J. Alderman, details a "Chicken Wire Roof and Method of Insulation". An insulated roof structure is formed on the industrial building by mounting a support framework on the purlins in the partially completed roof structure and moving the framework along the length of the purlins. A reel of wire mesh and a reel of sheet material are carried by the framework over each of the spaces between adjacent ones of the purlins and as the reels are progressively unrolled, layers of wire mesh and sheet material are applied to the spaces between the purlins while the support framework moves. Additional insulation can be blown upon or otherwise applied to the sheet material to fill the spaces between the purlins and hard sheets of roofing material are applied to the purlins as the support framework progresses across the structure. U.S. Pat. No. 4,696,138, dated Sep. 29, 1987, to Christopher A. Bullock, details "InsulationConfigurations and Method of Increasing Insulation Efficiency". Insulation configurations for the ceiling, floor and walls of structures include at least one layer of particulate or "blown" insulation, with a water vapor-permeable film or films isolating the layer or layers to limit air circulation and infiltration through the layers. Multi-layered insulation batts for building structures are detailed in U.S. Pat. No. 4,700,521, dated Oct. 20, 1987, to Craig H. Cover. The patent details thermal insulation for walls, ceilings and floors of building structures, which insulation contains alternating layers of low emissivity sheets and batts of low heat conductive material, laminated to form a single insulation batt. A "Method and Apparatus for Installing Insulation" is detailed in U.S. Pat. No. 4,724,651, dated Feb. 16, 1988, to Robert E. Fligg. Multiple sheets of vinyl-backed, fiberglass insulation are fastened side-by-side to each other to cover the area to be insulated. Purlin clips having an aperture therein are used to thread a band of metal therethrough for supporting the bottom side of the vinyl sheets at even intervals along their lengths.
It is an object of this invention to provide new and improved insulation configurations for insulating the attics and floors of homes, offices, and other structures, which insulation configurations are characterized by a first batt or particulate insulation layer of high density capping a second mass of low density, particulate insulation and resting on the ceiling in the attic and between floor joists, respectively, which high density insulation serves to isolate the low density particulate insulation to minimize air circulation through the low density insulation and combine in a synergistic manner with the low density insulation to increase insulating efficiency.
Another object of this invention is to provide an improvement to existing low density insulation in an insulated attic having a layer of sheetrock or other interior material attached to the bottom of supporting attic ceiling joists, wherein the mass of low density insulation is located between the ceiling joists, supported by the sheetrock, which improvement includes placing high density insulation having a selected thickness and density over the low density insulation to create a layered insulation configuration and minimize the movement of air through the insulation layers to thereby improve the thermal efficiency of the insulation.
A still further object of the invention is to provide an improved insulation configuration for the attics and floors of structures, which insulation configuration includes fiberglass batts or pillows of high density and thickness covering a quantity of low density insulation installed on sheetrock between the ceiling joists of the attic and between floor joists, which batts or pillows serve to isolate the low density insulation and combine with the low density insulation to substantially prevent air from circulating through the combined layers of insulation and increase the efficiency of the insulation configuration, while allowing moisture to move through the insulation layers without collecting therein and damaging the insulation, the underlying sheetrock or any structural members.
Yet another object of the invention is to provide an improved insulation configuration which includes a high density fibrous, loose-fill particulate, or blown insulation placed over a mass of low density insulation to at least partially isolate the low density insulation and create a high density-low density laminate which is characterized by decreased air infiltration and circulation.
Still another object of this invention is to provide a method for increasing the efficiency of insulation in the attics and floors of structures, which method includes the expedient of placing insulation batts or pillows of high density and selected thickness over the low density insulation, in order to isolate the low density insulation and minimize circulation of air through the resulting layers or cells of high and low density insulation.
A still further object of the invention is to provide a method for minimizing the circulation of air and heat through a layered insulation configuration characterized by a low density particulate or batt insulation and a high density insulation cap installed in the attics and floors of structures, which method includes installing high density insulation batts or pillows, or an alternative high density, water vapor-permeable insulation cap or cover, over the low density insulation, in order to substantially isolate the layered insulation combination from air infiltration and circulation.